Cross reference is made to U.S. patent applications Ser. No. 09/496,360, entitled xe2x80x9cApparatus and Method for Operating an Adjustable-Width Axle Assembly of a Crop Sprayerxe2x80x9d by Kenneth E. Weddle, now U.S. Pat. No. 6,199,769; Ser. No. 09/496,413, entitled xe2x80x9cApparatus and Method for Locking an Adjustable Width Axle Assembly of a Crop Sprayerxe2x80x9d by Kenneth E. Weddle, now U.S. Pat. No. 6,206,125; and Ser. No. 09/496,401, entitled xe2x80x9cApparatus and Method for Adjusting Height of a Chassis of a Crop Sprayerxe2x80x9d by Kenneth E. Weddle, each of which is assigned to the same assignee as the present invention, and each of which is filed concurrently herewith.
The present invention relates generally to a crop sprayer, and more particularly to an apparatus and method for operating a hydraulic suspension system of a crop sprayer.
A self-propelled crop sprayer is a work machine which includes a storage tank for storing liquid chemical such as herbicides, pesticides, and fertilizers that are to be sprayed onto crops which are growing in a farm field. The liquid chemical within the storage tank is sprayed onto the crops growing in the field by use of a nozzle assembly secured to a number of booms as the crop sprayer is advanced along the rows of the field.
It is desirable for a crop sprayer to be utilized in conjunction with a number of varying field conditions. For example, the distance between rows of plants varies from field to field. Accordingly, it is desirable to provide a crop sprayer which is capable of adjusting the distance between its two right wheels and its two left wheels so as to allow the crop sprayer to be advanced down the rows associated with the field without damaging or destroying the crops planted therein. In order to accommodate this need, crop sprayers have heretofore been designed with adjustable-width axle assemblies. However, heretofore designed adjustable-width axle assemblies have a number of drawbacks associated therewith. For example, adjustable-width axle assemblies which have heretofore been designed are relatively mechanically complex and include a relatively large number of components thereby increasing the costs associated with manufacture and operation of the crop sprayer. Moreover, certain adjustable-width axle assemblies which have heretofore been designed are susceptible to mechanical failure thereby reducing the useful life of a number of the components associated with the crop sprayer.
It should be appreciated that it is often necessary to apply a number of different spray applications during the growth cycle of the crops in the field. For example, it may be necessary to apply a first spray application when the crops are relatively young, but then subsequent spray applications may be required after the crops have grown to a substantial height. It is desirable for the crop sprayer to be configured such that the frame or other components associated with the sprayer are positioned at a sufficient enough height above the field surface so as to clear the tops of the crops as the sprayer is advanced through the field.
It is therefore not uncommon for a farmer or farmer""s cooperative to purchase two or more crop sprayers each of which has a different frame height for spraying crops of differing heights. However, this approach is relatively expensive and in some cases financially impossible for the farmer. In order to eliminate the need to purchase two or more different sprayers, a number of crop sprayers have been heretofore designed with adjustable-height mechanisms. However, such adjustable-height mechanisms which have heretofore been designed are generally mechanically complex and contain a number of expensive components such as a hydraulic lifters along with the associated fluid components thereby increasing the costs associated with manufacture and operation of the crop sprayer.
It should also be appreciated that the crop sprayer must also be configured to easily and efficiently traverse varying surface topography when being operated in the field. For example, due to the long boom arms which crop sprayers require in order to cover many rows of crops with a single pass, a small change in the angle at which the chassis of the crop sprayer is oriented results in a large height change at the end of the boom arm thereby reducing crop clearance of the lowered boom arm. Hence, crop damage may occur if the boom arms sway back and forth across a relatively large distance as the crop sprayer encounters varying surface topography or if the boom arms are significantly moved upwardly and downwardly as the crop sprayer executes a turn. Moreover, the environment in which the crop sprayer is operated, a farm field, is particularly prone to having varying surface topography. In particular, it is not uncommon for a farm field to include areas called xe2x80x9cwashoutsxe2x80x9d in which soil has been displaced to create gradually sloping low spots. Advancement of a crop sprayer over such washouts, as well as turning the crop sprayer in the field, has the potential to undesirably shift the center of gravity and disturb the stability of the crop sprayer.
Moreover, the chemical storage tank must placed on the crop sprayer in a position which allows the tank to clear the crops as the sprayer advances through the field. The presence of the storage tank in such an elevated position, along with the fact that the liquid chemicals in the storage tank cause the storage tank to be extremely heavy, causes the crop sprayer to have a higher center of gravity relative to other types of work machines or a road traveling vehicle.
Hence, in order to manage the forces encountered by crop sprayers during operation thereof, a number of suspension systems have heretofore been designed. For example, hydraulic suspension systems have heretofore been designed that utilize a number of hydraulic cylinders which are provided in an attempt to dampen forces encountered by the crop sprayer. However, as described above, a crop sprayer is particularly sensitive to forces acting upon it due to its relatively high center of gravity and such heretofore designed suspension systems have not been capable of adequately stabilizing a crop sprayer as it is advanced and maneuvered within a farm field.
What is needed therefore is a crop sprayer which overcomes one or more of the above-mentioned drawbacks. What is further needed is a crop sprayer having an adjustable-width axle assembly which can be quickly and easily utilized to change the operational width of the crop sprayer. What is also needed is a crop sprayer having an adjustable-height chassis which can be quickly and easily utilized to change the operational height of the crop sprayer. What is moreover needed is a suspension system for a crop sprayer which is capable of adequately stabilizing a crop sprayer as it is advanced and maneuvered within a farm field.
In accordance with a first embodiment of the present invention, there is provided a hydraulic suspension system for a work machine. The suspension system includes a first damping cylinder and a second damping cylinder. The suspension system further includes a first leveling cylinder which is fluidly coupled to the first damping cylinder via a first leveling fluid line and a second leveling cylinder which is fluidly coupled to the second damping cylinder via a second leveling fluid line. Moreover, the suspension system includes a first accumulator which is fluidly coupled to the first damping cylinder via a first damping fluid line and a second accumulator which is fluidly coupled to the second damping cylinder via a second damping fluid line. The first leveling fluid line is restricted relative to the first damping fluid line and the second leveling fluid line is restricted relative to the second damping fluid line.
In accordance with a second embodiment of the present invention, there is provided a method of operating a hydraulic suspension system of a work machine. The suspension system includes (i) a first damping cylinder, (ii) a second damping cylinder, (iii) a first leveling cylinder which is fluidly coupled to the first damping cylinder via a first leveling fluid line, (iv) a second leveling cylinder which is fluidly coupled to the second damping cylinder via a second leveling fluid line, (v) a first accumulator which is fluidly coupled to the first damping cylinder via a first damping fluid line, and (vi) a second accumulator which is fluidly coupled to the second damping cylinder via a second damping fluid line. The method includes the step of advancing first hydraulic fluid out of the first damping cylinder in response to retraction of the first damping cylinder. The method also includes the step of diverting a first portion of the first hydraulic fluid to the first accumulator. Moreover, the method includes the step of diverting a second portion of the first hydraulic fluid to the first leveling cylinder, wherein the first portion of the first hydraulic fluid is greater than the second portion of the first hydraulic fluid.
In accordance with a third embodiment of the present invention, there is provided a hydraulic suspension system for a crop sprayer. The suspension system includes a first damping cylinder and a second damping cylinder. The suspension system also includes a first leveling cylinder which is fluidly coupled to the first damping cylinder via a first leveling fluid line and a second leveling cylinder which is fluidly coupled to the second damping cylinder via a second leveling fluid line. The suspension system further includes a first accumulator which is fluidly coupled to the first damping cylinder via a first damping fluid line and a second accumulator which is fluidly coupled to the second damping cylinder via a second damping fluid line. The first damping fluid line possesses a first diameter, whereas the first leveling fluid line possesses a second diameter. The second damping fluid line possesses a third diameter, whereas the second leveling fluid line possesses a fourth diameter. The first diameter is greater than the second diameter and the third diameter is greater than the fourth diameter.
It is therefore an object of the present invention to provide a new and useful crop sprayer.
It is also an object of the present invention to provide an improved crop sprayer.
It is further an object of the present invention to provide a new and useful method of operating a crop sprayer.
It is yet another object of the present invention to provide an improved method of operating a crop sprayer.
It is moreover an object of the present invention to provide a crop sprayer in which the operational width of the crop sprayer may be quickly and easily altered.
It is also an object of the present invention to provide a crop sprayer in which the operational height of the crop sprayer may be quickly and easily altered.
It is moreover an object of the present invention to provide a crop sprayer which is relatively stable as the crop sprayer is advanced and maneuvered within a farm field.
The above and other objects, features, and advantages of the present invention will become apparent from the follower description and the attached drawings.